Employee Benefit Plans - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]      
Options assumed 102,586    
Percentage of savings of salary income on a pre-tax or after-tax basis 15.00%    
Matching employer contribution percentage 50.00%    
Employer contribution deferred by eligible participants percentage 3.00%    
Matching contribution expense recognized $ 119,000 $ 142,000  
Discretionary contribution expense     80,000
2011 Equity Incentive Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total shares reserved for possible issuance 500,000    
Issuance of stock option 0 0 0
Options outstanding, weighted average remaining contractual life 6 years    
Options exercisable, weighted average remaining contractual life 6 years    
Unrecognized compensation expense 0    
Compensation expense related to stock options recognized 0 0 0
2011 Equity Incentive Plan [Member] | Performance Shares [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Unrecognized compensation expense 756,000    
Compensation expense related to stock options recognized $ 358,000 $ 293,000 $ 112,000
Share awards vesting period 5 years    
2011 Equity Incentive Plan [Member] | United Group Banking Company of Florida [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Options assumed 102,586